It’s official: Johnny Clegg has finally become Phil Collins. Oh, a few sonic twists remain on Heat, Dust, & Dreams to let you know this guy once fronted Juluka, the first and best multiracial rock band in South Africa — a bumptious jive intro here, a Zulu refrain there. And Clegg’s heart is still huge and in the right place; he continues to tell a moving story in songs like ”The Crossing (Oslyeza).” But the music is now bloated, unfocused corporate hard pop. C-